Pump.



W. B. ERB.

PUMP.

APPLICATION FILED 0CT.2 1913.

Patented Apr. 27

1915. 3 SHEETS-SHEET I.

Ma @7. l/

W. B. ERB.

PUMP.

APPLICATION FILED ocT.2. 1913.'

Patented Apr. 27, 1915.

3 SHEETS-SHEET 2.

W. B. ERB.

PUMP.

APPLICATION FILED ocT.2. 1913.

Patented Apr. 27, 1915.

3 SHEETS-SHEET 3.

W ieg. 0, Y {N WQ 2 M N i ie WILLIAM B. ERB, OF CHICAGO, ILLINOIS.

PUMP.

ineen-ie.

Specication. of Letters Patent.

Patented Apr. 2?, 1915.

Application led October 2, 1913. Serial No. 792,954.

T0 all whom it may concern Be it known that I, WILLIAM B. ERB, a citizenof the United States, residing at Chicago, in the county of Cook andState of Illinois, have invented new and useful Improvements in Pumps,of which the following is a specification, reference being had to theaccompanying drawings, forming a part thereof.

'Ihe purpose ofthis invention is to provide an improved construction ofpumps specially designed for deep wells, operable in others, by whichthe water is elevated by thev use of compressed air both operating apiston for positive lift of the water, and also acting upon' the waterby injection ofthe air thereinto for inlating and elevating it.

It consists of the elements and features of construction shown anddescribed, as indi'- cated in the claims.

In the drawings z--Figure 1 is a vertical axial section of a well tubeand pump apparatus connected therewith embodying this invention. Figs.2, 3 and 4 are vertical sections ona larger scale than Fig. 1 of threevertically successive portions of the entire device. Fig. 5 is a sectionat the line, 5,- 5, on Fig. 6. Fig. 6 is a section at the line, 6,-6, onFig. 5. Fig. 7 is a section at the line, 7,-7, on Fig. 4. y

'Ihe well tube, 1, is presumed to be driven or sunken in the usualmanner in the well bore into the water-bearing stratum.- At its lowerend it terminates in an inlet fitting, 2, provided with a strainer, 3,below its inlet port, and a ball check valve, 4, above said port, thevalve seat, 5, being screwed into an inlet port after the inspection ofthe ball valve there-through into a cage, 5a, which forms the upper partof said fitting and through which the water which passes the ball valveenters the well tube. The inlet fitting also supports the pump cylinder,6, whose lower end is closed bythe coupling plug, 7, screwed into thecylinder, and onto the upper-end of the inlet fitting.

8 is a rubber cushion let into the upper end of the coupling plug, 7, toserve as a buer or yielding stop for the down strokeof the piston. Thewell tube at its upper end is connected by a coupling, 10, with anuplead pipe, 11, the cylinder, 6, being at its upper end fitted withinthe coupling, 10, so

f that the latter which is screwed into the upper end of the well tube,1, 'closes at the upper end* the annular-chamber, 12, whichis formedbetween the cylinder and the well tube. 'Ihe piston, 14, as will behereinafter more fully explained, is operated by compressed air admittedbelow it into the cylinder, lifting it to a pre-determined point ashereinafter explained, and the piston on its descent, however caused, isfollowed by the water entering from the chamber, 12, through ports, 15,at the upper end of the cylinder so that the cylinder above the pistonis filled with water ready to be lifted upon the next upwardl stroke ofthe piston.

In pumps. employing compressed air for operating the piston to elevatethe water, as such -pumps have been heretofore constructed, it has beencustomar to release the compressed air after each lifting stroke inorderto vacate the cylinder for the return stroke of the piston. Aspecific purpose of this invention is to avoid wasting the compressedair, and to utilize for further up-lifting and discharge of the waterthe expansive force of the compressed air below the piston which remainsafter the piston has been thus lifted by the compressed air forpositively lifting the water above it. For this purpose the cylinder, 6,is provided withra multiplicity of relatively small perforations, 16, ata level in the height of the cylinder which will be passed by the pistonand exposed below its lower end by the time the pistons upper endreaches and laps slightly upon the'ports, 15, leaving said ports stillmainly uncovered, for communication between the water space, 12,1and thecylinder chamber. When the parts, 16, are thus uncovered by the upwardmovement of the piston, the compressed air bclowf the latter in thecylinder is discharged in a multiplicity of jets into the water in thechamber, 12, and thence through the ports, 1 5, into the cylinder andthe up-lead pipe, 11, inflating and elevating the water and continuingand increasing its delivery upward to ultimate discharge.

At a distance above the highest position of the pump piston in thecylinder which will be desirably varied according to the differentcircumstances of each case, as, the depth of the well, the depth ofsubmergence of the cylinder below the level of the waterbearing stratum,and the degree of air pressure to be employed, there is located in theup-lead'pi'pe a column-retaining check valve,

17. Since the .piston stem must extend up within the-up-lead pipe, thewater passage therein is necessarily annular, and the check valve andits seat are conformed to this circumstance. Inasmuch as the check valveis to be mounted variably as to, its distance above the cylinder, theup-lead pipe is furnished at its lower part with a thin sleeve lining,lla, whose length covers the full range of probable variation ofposition of the check valve, and the check valve seat, 17a, beingsecured into a bushing ring, 17h, gripping an annular packing. ring, 17,is tted by means of said packing snugly within the said lining sleeve,11a, and is held lixedly suspended therein, in addition to its close fitin the sleeve, by means of a piston stem housing tube, 18, which iscoupled at its lower end to the upper end of a sleevelike hub, 17d, withwhich the check Valve seat is provided, and through which the pistonstem extends, said housing being screwed at its upper end into a hollowboss, 19, which projects from the top wall of a water chamber, 19, whichis mounted on the top of the up-lead pipe, and from which the finalwater discharge pipe 19e, leads olf. The check valve is seated by aspring, 17, coiled around the sleeve stem, 17, of said valve, saidsleeve stem being mounted for sliding freely on the sleeve hub, 17d, ofthe valve seat. The spring bears at its lower end upon the valve, 17,and is stopped at its upper end by the lower end of the coupling, 18a.The pump piston stem, 20, passes loosely through the hub sleeve, 17d, ofthe valve seat, the clearance around the stem being small so that thewater passes only to a limited extent around the stem through thehousing, 18. The boss, 19a, is provided with vent apertures, 19, openinginto the chamber, 19, at a point close to the top of said chamber. Theprimary purpose of these vent apertures is to permit the escape of airwhich may remain temporarily trapped below the check valve, 17 after thetension of the compressed air, originally operating, as above described,for lifting the water, has become reduced in such action so that it doesnot immediately find its way up'through the 4 Water. This residue of airremaining in the passages below the check valve would diminish thecapacity of the pump at each stroke thereafter, and it is important,therefore, that it should be allowed to escape, and this is eilectedthrough the space around the rod, 20, in the tubular connection of thecheck valve seat with the chamber, 19. In addition to this function,tlie ports, 19", serve to permit the easy upward movement and dischargefrom'the space around the piston stem in the connecting pipe, 18, of thewater, which may under some conditions of submersion be therein insteadof the air above mentioned. This is desirable because the piston stem,20, may have a coupling, 20a, located in said pipe, 18, which wouldoperate more or less as a piston displacing the water in the movement ofthe piston in either direction, and thereby causing considerableresistance to the movement of the piston.

rlhe compressed air is introduced into the cylinder through the pistonstem, which is for that purpose hollow, and which for the same purposeextends up through the water chamber, 19, a stuling box, 22, beingprovlded on the upper side of said chamber through which the pistonextends upward. Upon the upper side of said chamber, 19, there ismounted a housin the purpose of which is to afford means for giving thecompressed air access to the cavlty of the piston stem, and controllingentrance of the compressed air therethrough, as will hereinafter appear.For this purpose the pump piston stem at its upper end comprises a valvemember, 24, and a cam member, 25, the two being in one piece which ishollow from its lower end upward to a point near its upper end, which istapered, as shown, at 25, to form a cam for the purpose hereinafterexplained; and in said tapered portion an aperture, 25, leads from thesurface to the vinterior cavity of said member. Saidl valve-and-cammember is screwed at its lower end onto the upper end of the lowertubular portion of the pump piston stem, and immediately above the valveportion, 24, by which it is thus attached, it is cut. away at oppositesides to form the lateral openings, 25, 25, leading from its interiorcavity into the chamber of the piston stem housing, 2 3. Onto the upperend of the piston-stem-housing, 23, there is bolted fast a member, 30,the lower end of said member and the upper end of the housing, 23, beingprovided with mated flanges for securing them together. The member, 30,is, or comprises substantially a continuation of the piston housing, butwith a cavity of such diameter as to beI fitted snugly piston-wise bythe valve-andcam-member, 24,-25, of the pump piston stem; and said stemis extended upward, but without being hollow, in the rod portion, 26,and terminates in a second cam member` 27.

The member, 30, has mounted upon it at a position of its lengthintermediate the lower end in which the piston cam member,

g, 23, for the Vupper end portion of the plston,

25, is seated and the upper end portion in which the cam member, 27, isseated, oppositely transversely projecting valve chamanaemia ancedvalve, 34, which has a short range of reciprocation in said chamber andhas in each of its opposite heads a small port, 34, leading from thecavity of the valve into the cavity of the. valve chamber. The valvechamber is furnished at its upper side with a compressed air inlet port,31, at which is connected a compressed air supply pipe, 35, providedwith a manually operable shut-olf valve, 36. It will be understood thatthe pipe, 35, leads to a compressed air supply chamber not shown, thepipe, 35, bein hereinafter referred to as the source o compressed air.'lhe valve chamber, 31, has an exit port, 31h, diametrically op ositethe inlet port, 3l, and the valve, 34, as corre-- sponding inlet andexit ports, 34b and 34,-

whic'h register with the ports, 31a and 31h, respectively, when thevalve, 34, is at one limit,-(the right hand in `Fig. 5)-of itslongitudinal movement in the chamber, 31. 'llhe valve, 34, is guided insaid longitudinal movement and prevented from rotating in the chamber bya guide stud, 37, which projects from the upper side of the chamber wall into a slot, 34, of the valve which is, in fact, a continuation ofthe port, 34", and has the effect of causing the interior cavity of thevalve to be at all times in communication with the inlet port, 31,leading from the. compressed air source. rlhe chamber, 31, is incommunication at its opposite ends, respectively, with valve\ chambers,28 and 29, said communication being effected by the passages, 28 and 29,respectively, leading laterally from said balanced valve chamber andentering laterally into the valve chambers, 28 and 29, respectively, atthe inner ends of said valve chambers, respectively. lln said lastmentioned valve chambers there are provided piston valves, 28", 29",which are normally held seated over the inlet ports, 28a and 29, bysprings, 28e, 29. Said valve chambers open axially with respect to thebosses in which they are formed, radially into the cavity of the pistonstem housing, 30, and said valves are provided respectively with stems,28 and 29d, which lit the extension of said valve chambers into thecavity of said pump piston stem housing, said stems havin axial boresfrom their inner `ends terminating in said housing chamber back of thepoint at which the stems join the body of the valve, and said axialports are there connected by laterallyleading ports, 28e, 29", with thevalve chambers, respectively; so that when the valves are pushed back intheir chambers against the resistance of their respective springs,communication is opened between the chambers-.of 'said yalvesrespectively and the cavity of the piston stem housing in the member,30; and thence throughthe piston stemto the pump cylinder below the pumppiston; and the valves, 28b and 29", are by the same movement moved touncover the ports,

28a 'and 29, leading from the balanced valve chamber, 31, which is thusput in communication alternately at opposite ends with the pump cylinderbelow the piston. The cam members, 25 and 27, on the pump piston stem atthe opposite extremities of the rod portion, 26, thereof, are adapted toencounter the ends of the hollow valve stems, 28d and 29d, in theopposite strokes of the piston so as to open said valves, 28b and 29",alternately at opposite stages of the pump pistons movement.

The operation of the valve mechanism above described is as followsz-Assuming the, piston, 14, to be at the bottom of its stroke in thecylinder, the cam member, 27, will be in a position at which havingencountered the stem of the valve, 29h, and

thrust that valve open, it is holding the same in open positionmaintaining air communication between the cavity of the housing, 30, andthe right hand end of the balanced valve chamber, 31. At this stage, thebalanced valve, 34, is at the position shown in Fig. 5, openingcommunication from the source of compressed air into the passage,

39, leading from the lower side of the balanced valve chamber and thencehorizontally in the lower side of the casting forming said chamber, `tothe face thereof by which it is mounted upon the member, 30, where saidpassage registers with a duct, 40, formed in the latter and leading tothe lower end thereof Where it opens into the cavity of the housing, 23.By this passage the compressed air is admitted through 'theports, 25,into the axial cavity of the hol^ low piston stem, 20, and thereby intothe cylinder, 6, belowy the piston. 'llhe several parts being at rest inthis position, upon the operator opening the valve, 36, and admittingthe compressed air, the iston will be forced upward inthe cylin er,lifting the water above itin the cylinder, and in the up-lead pipe pastthe check valve, 17, and,-assuming the up-lead pipe and chamber, 19, andpassage pipe, 20, to be already full of water,.-the water will be bythis movement discharged from the upper-end of said discharge pipe. Whenin this movement the lower end of the piston passes and uncovers theports, 16, the compressed air below the piston forcing its way past thecheck valve, 50, is .discharged in a multiplicity of jets out throughthe ports, 16, out 1nto the chamber, 12; and thence, passmg around thepiston back and through the pots, 15, inflating the Water inthe cylinderi .an

11p-lead pipe above the piston, and thereb uplifting the body of thewater therea ove, it causes further discharge from the discharge pipe,19. In the upward movement of the piston and about the time it passesJand uncovers the ports, 1 6,

iao

the'lower end of the piston valve cam member, 25,--that is, the portionthereof below the ports, ,enters the housing member, 30, and, operatingyas a valve therein, shuts o' the communication of the compressed airwith the cavity of the hollow piston stem.

Substantially simultaneously with the cut- -ting oif of the compresseda1r communication with the piston stem, whichuis effected by means ofthe valve end, 24, as described, the upper cam end, 25, encounters thestem of the valve, 28", and thrusts the same inward, opening that valve.The supply of compressed air being cut oiil and the compressed airexpanding by discharge into the .water for inating and lifting the same,as described, the tension of the air in the cylinder below the pistonand in the cavity of the piston stern, will be reduced and the valve, 28", being open establishingcommunication for said air under reducedtension withthe left hand end' of 'the balanced valve chamber, 31, thetension of the air in that. end of thechamber being reduced willimbalance the valve and cause it to be moved tothe left, cutting yoii"the communication whichy it controls withv the compressed air source.'Ihe movements described of the balanced valve result because of therelatively small communication alorded by the port, 34, from theinterior of the valve to the right hand end of the chamber, incompari'son Iwith the vent for escape of compressed air ailorded by thepassages 28a and 29B. The compressed air in the cylinder below thepiston continuing to expand and inflatie, elevate 'and discharge thewater from above the piston, the tension of said air will eventually bereduced so that it will no longer-support the piston and its stem andits .a-ppurtenantt members, and the piston will descend in the cylinderto the bottom thereof. In the last short increment of the descendingmovement ofthe pump piston, the cam member, 27, at the upper end of therod member, 26, of the piston stem encounters the Stem 4of the valve,29", and opens said valve; thereby effecting communication from` thechamber of the housing, 30, to

the vright hand end of the balanced valve chamber, causing said valve tobe again unbalanced, which will result in its movement .in the oppositedirection from that previously occurring, and its arrival at theposition shown in Fig. 5 at which free4 communication is opened throughit from the compressedl airsource to the cavity of the housing, 23'. Thepiston continuing to descend, the valve member, 24, onthe piston stememerges from its seat in the housing,

@30, and the ports, 25, are uncovered, admitting the compressed air tothe cavity of the` hollow stem, and .thence into the cylinder below thepiston, whereupon the cycle of movement above described will berepeated.

The pump piston'is provided at its lower end with a check valve, 50,which controls ports, 51, in the lower end section of the piston throughwhich the water is admitted to pass the check valve and enter the space,14D, between said lower section, 14, and the main body of the piston,14. The purpose of this is to adapt the piston to pick up from thebottom of the cylinder any water which may have obtained entrance byleakage past the piston, or otherwise, so as to permit the piston atfull stroke to descend to the bottom of the cylinder and thus obtain itsfull range of action upward. The water thus picked up and carried in thespace, 14h, will be ejected by the air, as

'above described, when the piston rises so as to bring the space, 14",opposite the. perforations, 16.

I claim 1. In a pump, in combination with a pump piston and a cylinderin which it reciprocates, a by-pass from a lower to a higher point' onthe cylinder chamber around a ,fcertaln position of the piston thereinat the upper part of its stroke; a

hollow piston stem opening into the cylinder below the piston; a sourceof compressed ai-r and meansfor alternately admitting it to andexcluding it from the piston stem, said means comprising av valve whichis operated by the compressed air, and devices Operated by theup-and-down movement; of the piston stem for unbalancing the airpressure on said valve oppositely at.

opposite stages of the piston stems movement.

2. In combination with a pump piston and a cylinder in which itreciprocates, a bypass from a lower to a higher point .of the cylinderchamber around a certain position of the piston therein at the upperpart of its stroke; a source ofcompressed air; a passage leading fromthe piston chamber below thel piston to said compressed air source; adevice for controlling communication through said passage; a valveoperated by the piston forcontrolling said passage at a pointintermediate the first-mentioned controlling device and the pumpcylinder; an auxiliary passagenot controlled by the lastmentioned valveconnecting the previouslymentioned passage with the first-mentionedcontrolling device, and valves operated by the piston at opposite stagesof its stroke for controlling the communication of said auxiliarypassage with said first-mentioned controlling' device.

3. In-combination with a pump piston and a pump cylinder in which itreciprocates, an up-lead pipe connected to theupper end and" leading toa discharge; a check valve in the up-lead pipe opening dischargeauieaaaetain' position of the piston therein at the upper part of its stroke; ahollow piston stem opening into the 4cylinder below the piston; a sourceof compressed air and means for alternately admitting it to andreleasing it from the piston stem, said means comprising a valve whichis operated by the compressed air, andy devices operated by theup-and-down movement of the piston stem for unbalancing the air pressureon said valve oppositely at `opposite stages of the movement of thepiston stem.

4. ln combination with a well tube or casing, a pump cylinder supportedwithin the casing and positioned therein to afford water space betweenit and the casing wall; a check valve at thed foot of the caslngadmitting water to said water space; a piston mounted for reciprocationin the cylinder, the latter having communication with Said water spacenear the upper limit of the pistons stroke in the cylinder, and also atits upper part below the pistons position at said limit,4 whereby aby-pass` is formed around the piston at said position; a hollow pistonstem opening into the pump cylinder below the -piston; a source ofcompressed air and means for alternately admitting it to` and releasingit from the piston stem, said means comprising a valve which is operatedby the compressed air, and devices operated by the up-and-down movementof the piston stem for unbalancing the air pressure on said valveoppositely at the opposite stages of the lpistons movement.

5. lln combination with a pump piston and a pump cylinder in which itreciprocates, a by-pass from a lower to a higher point of the cylinderchamber around a certain position of the piston therein at the upperpart of its stroke; a hollow piston stem opening into the cylinder belowthe piston; a source of compressed air and means for alternatelyadmitting it to and releasing it from the piston stem; Said meanscomprising a piston valve and its chamber provided with means forcommunieating with the source of ce mpressed air adapted to admitbalanced pressure to the valve, passages aording communication from thepump piston chamber belew the pistonto the piston valve chamber at'opposite sides of the valve therein, and means by vwhich the pumppiston stem opens said communications alternately at opposite stages ofits stroke. 4

6. lncombination with a pump piston and a pump cylinder in which itreciprocates, a by-pass from a lower to a higher point of thepump'cylinder around a certain position of the piston therein at theupper part of 'the stroke of the latter; a compressed-air-controllingdevice and a passage therefrom to the :pump cylinder below the piston,said controlling device comprising a balanced piston valve and itschamber, said chamber having two inlet ports at o-pposite sides of thepiston valve; a valve device operating in the compressed-air passagewhich leads to the pump cylinder for cutting ofi' communication betweenthe same and the compressedair-controlling device; air connections notcontrolled by said valve leading from said passage to said inlet ports;valves which control said connections respectively, and means by *whichthe piston operates said valves alternately at opposite stages of itsstroke.

7. In combination with a pump piston and a pump cylinder in which itreciprocates, an up-lead pipe leading from its upper end; a by-pass froma lower to a higher point of the cylinder chamber around a certainposition of the piston therein at the upper part of its stroke; a hollowpiston stem opening into the cylinder below the piston; a housing forthe piston stem above the uplead pipe and a iitting which closescommunication of said housing with the up-lead pipe andV constitutes astuiing box for the stem; a piston valve member on the stem above thestuiiing boX; a seat for said piston valve in the housing; acompressed-aircontrolling device and a passage therefrom 'leading intothe piston-stem housing between said stuiing box and the piston valveseat, the piston stem having an opening leading from its cavity int thecavity of said housing for communication with said passage, saidcontrolling device comprising a balanced piston valve and its chamber,the latter having ports for air communication at opposite sides of thepiston valve vtherein; ducts from said ports to the piston housing abovesaid piston valve member; valves controlling said ducts, the piston stemhaving means for operating said valves alternately -at opposite stagesof its stroke.

v 8. In combination with a well tube.or casing, a pump cylindersupported within the casing and positioned therein to afford water spacebetween it and the casing wall; a piston mounted for reciprocationin thecylinder, the latter having communication with said water space near theupper limit of the piston'Js stroke in the cylinder, and also at itsupper part below the pistons position at said upper limit, whereby aby-pass for air is formed around the piston at said position, thelast-mentioned of said communications being by means of a. multiplicityof relatively small perforations for subdividing the air into small jetsat its emergence into the water; a hollow piston stem opening'into thepump cylinder below the piston; a source of compressed air and means foralternately admitting it to and releasing it from the piston stem.

9. lin combination with a pump piston and a cylinder in which itreciprocates; av

iio

previously-mentioned passage with the irst mentioned controlling device,and valves operated by the .piston at opposite stages of its stroke forcontrolling the communication of said auxiliary passage with thefirst-mentioned controlling device.

10. In a pump, in combination with a pump piston and a cylinder in whichit reciprocates, an up-lead pipe from the upper end of the cylinder forwater discharge; a hollow piston stem opening into the cylinder belowthe piston; a source of compressed air and means for alternatelyadmitting it to and excluding it from the piston stem;

means for opening communication for the compressed air from the pistonstem into the up-lead pipe at a pre-determined point in the risingmovement f the piston, and

means for controlling the admission o fcompressed air to the piston stemcomprising a valve and two air connectionsfor operating it in oppositedirections, said air connections leading from the piston stem; valveswhich control said connections respectively, and means carried by thepiston stem for operating said valves respectively at opposite stages ofthe pistonsmovemen 11. In a pump, 1n 'combinatlon with a I p ump pistonand a cylinder in which it reclprocates, a well tube within which thecylinder is positioned having access for water to the space around thecylinder, the cylinder having communication near its upper end with saidWater space for receiving water therefrom above the piston; means forsupplying and .intermitting the supply of compressed air to the cylinderbelow the piston to cause reciprocation of the piston, the cvlinderhaving ports for communication from its chamber with the water spacearound it in the well tube at a positionto be uncovered by the upwardmovement of the piston near the upper limit of its stroke, for admittingthe compressed air from below the lpiston into the water space aroundthe cylinder and thence back into the cylinder above the piston.

12. In a pump, in combination with a pump piston and a cylinder in whichit 15eciprocates, a well tube within which the cylinder is positionedhaving access for water to the space around the cylinder, the cylinderhaving communication near its upper end with said water space forreceiving water therefrom above the piston; means for supplying andintermitting the supply of compressed air to the cylinder below thepiston to cause reciprocation of the piston,

'the cylinder having ports for communication from its chamber with thewater space around it in the well tube at a position to be uncovered bythe upward movement of the piston near the upper limit of its stroke,for admitting the compressed air from below the piston into the waterspace around the cylinder and thence back into the cylinder above thepiston; a supplemental plston below the main piston having portsextending through it, and a check valve above said supplemental pistonopening upward, whereby water which may accumulate in the bottom of thecylinder may be lifted by said supplemental piston and discharged by theair through said ports. l

13. Incombination Awith a pump piston and a cylinder in which itreciprocates, an up-lead pipe connected to the upper end of thecylinder; a water chamber at the up er end of the up-lead pipe; means bywhich the piston stem is extended water-tight through the top of saidchamber; a houslng for the piston stem above said chamber; a conduitleading from a source of compressed air opening into the housing, thepiston stem ,having an openin into its cavity for compressed air to saidconduit.

14. In a pump, in combination with a pump piston and a cylinder in whichit reciprocates, a source of compressed air and means for alternatelyadmitting it to and excluding it from the cavity of the cylinder belowthe piston, said means comprising a balanced valve device; airconnections leading from the cylinder below the piston to opposite sidesof such valve for unbalancing the latter; valves controlling saidcommunications, and cams on the piston stem for operating said valvesalternately at opposite stages of the pistons movement.

15. In a pump, in combination with a cylinder and piston therein andmeans for discharging compressed air into the up-take water passage`above the piston, a check .valve in said up-take passage; a housingwhich supports the check valve seat extend- License `ing to the top ofsaid 11p-take pipe, the piston stem extending loosely through saidhousing and the housing having vent apertures at its upper end above theup-take plpe.

16. In a pump', in combination with the pump piston, a cylinder in whichit reciprocates; a source of compressed air; a conduit therefrom to thecavity of the cylinder below the piston; means for opening communicationfrom said cavity into the space above the piston at a pre-determinedpoint in the upward movement of the piston; a balanced yvalve device foralternately admitting and excluding compressed air from said conduit;means for `operating said balanced valve comprising air connections fromthe space in the vcylinder below the piston to opposite sides of thebalanced valve; valves which control said connections, and meansoperated by the pistons movement for opening said valves `alternately atopposite stages of the pistons movement.

In testimony whereof, ll have hereunto set my hand at Chicago,llllinois, this 29th day of September, 1913.

WllLLIAM B. ERB. Witnesses: p

BoBT. N. BURTON,

EDNA M. MACINTOSH.

